Lochinvar EW 250 Designer's Manual

Brand: Lochinvar

Model: EW 250

Type: Designer's Manual

This manual is also suitable for

DESIGNER’S GUIDE EFFICIENCY+

WATER HEATER

150,000 – 300,000 Btu/hr

Dear Specifier/Project Manager,

At Lochinvar, we have long recognized the importance of innovation to any

product or service. Those who enter into business must also accept the challenge

of meeting constantly changing needs.

The designer’s guide you are now holding has been designed to make it more

convenient for you to select the perfect Lochinvar water heater for your projects

and provide correct specifications for your teams.

All information has been organized and presented in a succinct, easy-to-use

manner, so you can use and share information confidently and with minimal

effort.

However, it is important to remember that this guide is not intended to replace our

installation manual. Installers should still refer to our installation manual for

specific installation instructions.

We hope our manual will make your work easier and more productive.

As always, we greatly appreciate your input on additional improvements for

the future.

Thanks once again for specifying the Lochinvar family of quality standard

and custom-built water heaters and boilers.

Sincerely,

Lochinvar Corporation

Lochinvar Corporation • 615-889-8900 / Fax: 615-547-1000

Lochinvar DESIGNER’S GUIDE EFFICIENCY+ WATER HEATER 615-889-8900 1

Clearances . . . . . . . . . . . . . . . . . . . . . .3

Codes . . . . . . . . . . . . . . . . . . . . . . . . .2

Combustion & Ventilation Air . . . . . . . . .3

Contaminants . . . . . . . . . . . . . . . . . . . .5

Conventional Venting . . . . . . . . . . . . . .8

Direct Venting . . . . . . . . . . . . . . . . . . .11

Electrical Requirements . . . . . . . . . . . .17

Gas Supply . . . . . . . . . . . . . . . . . . . .15

General Venting . . . . . . . . . . . . . . . . .13

Location of Unit . . . . . . . . . . . . . . . . . .2

Low Water Temperature Delivery . . . . .16

Outdoor Installation . . . . . . . . . . . . . .14

Outdoor Use . . . . . . . . . . . . . . . . . . . .3

Pump Operation . . . . . . . . . . . . . . . . .16

Relief Valve . . . . . . . . . . . . . . . . . . . .17

Water Connections . . . . . . . . . . . . . . .16

Water Treatment . . . . . . . . . . . . . . . . .17

Water Velocity Control . . . . . . . . . . . .15

Figures & Tables Index

FIG. 1 Water Heater Equipment

and Control Orientation . . . . .3

FIG. 2-5 Combustion & Ventilation Air .4,5

FIG. 6 Barometric Damper

Installation . . . . . . . . . . . . . . .8

FIG. 7 Multiple Unit Barometric

Damper Installation . . . . . . . . .8

FIG. 8 E+ DirectAire Vent With

Sidewall Air Inlet . . . . . . . . .10

FIG. 9 E+ DirectAire Vent With

Rooftop Air Inlet . . . . . . . . . .10

FIG. 10 Horizontal Direct Vent . . . . . .12

FIG. 11 Horizontal Direct Vent Caps .12

FIG. 12 Multiple Sidewall

Direct Vent Caps . . . . . . . . .13

FIG. 13 Vertical Direct Vent . . . . . . . .13

FIG. 14 Outdoor Venting . . . . . . . . .14

TABLE A. Clearances From

Combustible Construction . . . .3

TABLE B. Conventional Venting,

Vent Connection Size . . . . . . .8

TABLE C. E+ DirectAire Vent Kits . . . . .10

TABLE D. Horizontal Direct Vent Kits . . .12

TABLE E. Vertical Direct Vent,

Flue And Air Inlet Sizes . . . . .13

TABLE F. Outdoor Vent Kits . . . . . . . . .14

TABLE G. Gas Supply Pipe Sizing . . . .15

TABLE H. Inlet Gas Pressure . . . . . . . . .15

TABLE I. Required Temperature Rise . .16

TABLE J. Required Pump Performance 17

TABLE K. Common Water

Manifold Size . . . . . . . . . . .17

TABLE L. Amp Draw Data . . . . . . . . . .17

Water Heater Piping Diagrams

Single Heater – Single Tank . . . . . . . . .A1

Single Heater – Two Tanks . . . . . . . . .A2

Two Temperature Installation

Single Heater – Single Tank . . . . . . .A3

Two Heaters – Single Tank . . . . . . . . .A4

Two Heaters – Two Tanks . . . . . . . . . .A5

Multi-Stack Frame w/Water Heaters

and Storage Tank . . . . . . . . . . . . . . . .A6

Table of Contents

2 Lochinvar DESIGNER’S GUIDE EFFICIENCY+ WATER HEATER 615-889-8900

Lochinvar

CODES

The equipment MUST be installed in

accordance with those installation regulations

in effect in the local area where the installation

is to be made. These MUST be carefully

followed in all cases. Authorities having

jurisdiction MUST be consulted before

installations are made. In the absence of such

requirements, the installation MUST conform

to the latest edition of the National Fuel Gas

Code, ANSI Z223.1. Where required by the

authority having jurisdiction, the installation

MUST conform to American Society of

Mechanical Engineers Safety Code for

Controls and Safety Devices for Automatically

Fired Boilers, No. (CSD-1). All boilers conform

to the latest edition of the ASME Boiler and

Pressure Vessel Code, Section IV. Where

required by the authority having jurisdiction,

the installation MUST comply with the

Canadian Gas Association Code, CAN/CGA-

B149.1 and/or B149.2 and or local codes.

LOCATION OF UNIT

Locate the unit so that if water connections

should leak, water damage will not occur.

When such locations cannot be avoided, it

is recommended that a suitable drain pan,

adequately drained, be installed under the

unit. The pan MUST NOT restrict

combustion airflow. Under no circumstances

is the manufacturer to be held responsible

for water damage in connection with this

unit or any of its components.

•

Water Velocity – Flow Rate

(See page 16 for Required

Temperature Degree Rise chart.)

•

Factory Supplied

Pump Capacity

(See page 16 for Pump Operation.)

•

Manifold Pipe Size

When using more than one heater

(See page 17 for Common Water

Manifold Size for Multiple Water

Heater Installation table.)

•

Storage Tank Circulating

Tappings

(See page 17 for Manifold Pipe

Size.)

•

Placement of Cold Water Inlet

and Building Return

(See Appendix A for Water Heater

Piping Diagrams.)

•

Water Hardness

(

See page 16 for Water Treatment

Information.)

In designing a hot

water heater system,

pay special attention to:

The indoor unit MUST be installed so that

the ignition system components are

protected from water (dripping, spraying,

rain, etc.) during appliance operation and

service (circulator replacement, control

replacement, etc.)

Units located in a residential garage

MUST be installed so that burners and

ignition devices have a minimum clearance

of 18" (46 cm) above the floor. The units

shall be located or protected to prevent

physical damage by a moving vehicle.

The appliance MUST be installed on a

level floor. A combustible wood floor may

be used without additional bases or special

floor buildup. Maintain required clearances

from combustible surfaces.

The appliance MUST NOT be installed on

carpet or other combustible material other

than wood flooring.

SPECIAL LOCATION:

OUTDOOR USE

Outdoor models have additional location

and clearance requirements. These requirements

must be adhered to carefully, since wind, rain,

snow and cold cannot be controlled in outdoor

applications. See Outdoor Installation, in the

venting section on page 15.

COMBUSTION & VENTILATION AIR

Provisions for combustion and ventilation air

MUST be in accordance with Section 5.3, Air

for Combustion and Ventilation, of the latest

edition of the National Fuel Gas Code, ANSI

Z223.1; or in Canada, the latest edition of

CGA Standard B149 Installation Code for

Gas Burning Appliances and Equipment; or

provisions of the local building codes.

Lochinvar DESIGNER’S GUIDE EFFICIENCY+ WATER HEATER 615-889-8900 3

(TABLE A)

CLEARANCES FROM COMBUSTIBLE CONSTRUCTION

RIGHT SIDE 1”

REAR 1”

LEFT SIDE 6” (24” suggested for service)

FRONT 3” (24” suggested for service)

Suitable for closet installation

TOP 3”

*Allow sufficient space for servicing pipe connections, pump and other

auxiliary equipment, as well as the appliance.

(FIG. 1) WATER HEATER EQUIPMENT &

CONTROL ORIENTATION

FLUE PRODUCTS

VENT

HOT WATER

OUTLET

BURNER INSPECTION

PORT

GAS

CONNECTION

COLD WATER

INLET

BACK

TERMINAL STRIP

(INSIDE)

FRONT

DRAIN

120V ELECTRICAL

CONNECTION

AIR INLET

EW 150-300

LEFT SIDE

CAUTION!

EXHAUST FANS: Any

fan or equipment which

exhausts air from the

equipment room may

deplete the combustion

air supply and/or cause

a down draft in the

venting system. If a

fan is used to supply

combustion air to the

equipment room, it

must be sized to make

sure that it does not

cause drafts which

could lead to nuisance

operational problems

with the water heater.

4 Lochinvar DESIGNER’S GUIDE EFFICIENCY+ WATER HEATER 615-889-8900

The equipment room MUST be provided with

properly sized openings to assure adequate

combustion air and proper ventilation, when

the unit is installed with conventional venting or

sidewall venting.

If air is taken directly from outside the building with

no duct, provide two permanent openings:

A. Combustion air opening, with a

minimum free area of one square inch per

4000 Btu/hr input (5.5 cm

per kW).

This opening MUST be located within 12

”

(30 cm) of the bottom of the enclosure.

B. Ventilation air opening, with a minimum

free area of one square inch per 4000

Btu/hr input (5.5 cm

per kW).

This opening MUST be located within 12

”

(30 cm) of the top of the enclosure.

If combustion and ventilation air is taken from the

outdoors using a duct to deliver the air to the

mechanical room, each of the two openings

should be sized based on a minimum free

area of one square inch per 2000 Btu/hr

(11 cm

per kW).

If air is taken from another interior space, each

of the two openings specified above should

have a net free area of one square inch per

1000 Btu/hr (22 cm

per kW) input, but

not less than 100 square inches (645 cm

Lochinvar

(FIG. 4) COMBUSTION AIR FROM AN

INTERIOR SPACE

(FIG. 3) COMBUSTION AIR THROUGH

DUCTWORK

(FIG. 2) COMBUSTION AIR DIRECT FROM

OUTSIDE

EXAMPLE OF

SIZING FOR

COMBUSTION

& VENTILATION

AIR OPENINGS

(WATER HEATER

WITH 300,000

BTU/HR INPUT):

When combustion and

ventilated air is taken

from directly outside the

building (FIG. 2), divide

the total BTU’s by 4,000.

This yields 75 sq.in. of

“Free Area” without

restriction.

(300,000/4,000 =

75 sq.in.)

Since the air opening is

50% closed due to

screens and louvers, the

total opening MUST be

multiplied by 2.

(75 sq.in. x 2 =

150 sq.in.)

This project requires one

Ventilation Air Opening

of 150 square inches

with louver dimensions

of 12” x 15”= 180

sq.in. and one

Combustion Air Opening

of 150 square inches

with louver dimensions

of 12” x 15”.

Lochinvar DESIGNER’S GUIDE EFFICIENCY+ WATER HEATER 615-889-8900 5

If a single combustion air opening is provided to

bring combustion air in directly from the outdoors,

the opening MUST be sized based on a

minimum free area of one square inch per

3000 Btu/hr (7 cm

per kW). This opening

MUST be located within 12

”

(30 cm) of

the top of the enclosure.

CONTAMINANTS

Combustion air drawn from an interior or

exterior space MUST be free of any chemical

fumes which could be corrosive to the water

heater.

Burning chemical fumes results in the formation

of corrosive acids which attack the water

heater and cause improper combustion and

premature failure of the water heater and vent.

These fumes are often present in areas where

refrigerants, salts, and solvents are used.

Therefore, be aware of swimming pool

equipment, water softening, and cooling

system placement.

VENTING

General

Vent installations for connection to gas vents or

chimneys should be in accordance with Part 7,

“Venting of Equipment”, of the latest edition of

the National Fuel Gas Code, ANSI Z223.1, or

applicable provisions of the local building

codes.

The connection from the appliance vent to the

stack MUST be as direct as possible and

sized correctly, using the proper vent table.

The horizontal breaching of a vent MUST

have at least 1/4

”

rise per linear foot.

The horizontal portions shall also be supported

for the design and weight of the material

employed to maintain clearances, prevent

physical damage and separation of joints.

The connection from the appliance vent to the

stack or vent termination outside the building

MUST be made with listed Type “B” double

wall vent (or equivalent) for conventional vent

applications.

When utilizing direct vent capabilities,

connections MUST be made with AL29-4C

stainless steel (or equivalent) vent material.

Material should be sized according to vent sizing tables

(FAN column) in the latest edition of the National Fuel

Gas Code.

CAUTION! Under no circumstances should the

equipment room be under a negative pressure

when atmospheric combustion equipment is

installed in the room.

(FIG. 5) COMBUSTION AIR FROM A

SINGLE OPENING

NOTE:

The weight of the

venting system MUST

NOT rest on the water

heater. It should be

properly supported.

WARNING

Vent connectors serving

gas appliances, which

operate under a

negative vent pressure,

shall not be connected

into any portion of

mechanical draft

systems operating under

positive vent pressure.

6 Lochinvar DESIGNER’S GUIDE EFFICIENCY+ WATER HEATER 615-889-8900

The vent materials and accessories, such as

firestop spacers, thimbles, caps, etc., MUST

be installed in accordance with the

manufacturer’s listing.

The vent connector and firestop MUST provide

correct spacing to combustible surfaces and

seal to the vent connector on the upper and

lower sides of each floor or ceiling through

which the vent connector passes.

Any improper operation of the common

venting system in the existing building should

be corrected when new equipment is installed,

so that the installation conforms to the latest

edition of the National Fuel Gas Code, ANSI

Z223.1.

The efficiency of this appliance allows its

products of combustion to be vented through a

smaller vent pipe when compared to units of

the same Btu/hr capacity. For this reason,

resizing common venting systems is

recommended for proper operation.

When resizing any portion of the common

venting system, it should be resized to

approach the minimum size as determined

using the appropriate tables (FAN column) in

the National Fuel Gas Code.

Failure to resize a common venting system

could lead to the formation of condensate and

premature deterioration of the vent material.

Flue gas condensate can freeze on exterior

walls or on the vent cap. Frozen condensate

on the vent cap can result in a blocked flue

condition. Some discoloration to exterior

building surfaces can be expected. Adjacent

brick or masonry surfaces should be protected

with a rust resistant sheet

metal plate.

Vent connectors serving appliances vented by

natural draft shall not be connected to

any portion of a mechanical draft system

operating under positive pressure.

Connection to a positive pressure stack may

cause flue products to be discharged into the

living space causing serious health injury.

Locate units as close as possible to a chimney

or gas vent.

VENT TERMINATIONS

When locating the vent cap, consider the

effects of snow, leaf dropping, etc., to insure

that no blockage occurs.

The distance of the vent terminal from adjacent

public walkways, adjacent buildings, windows

that open and building openings MUST

comply with the latest edition of the National

Fuel Gas Code, ANSI Z223.1.

The vent terminal should be vertical and

exhaust outside the building at least 2 feet

(0.6 m) above the highest point of the roof

within a 10 foot (3.05 m) radius of the

termination.

Lochinvar

IMPORTANT!

The vent cap should

have a minimum

clearance of 4 feet

horizontally from electric

meters, gas meters,

regulators, air inlets and

air relief equipment.

Additionally, the vent

cap should never be

located above or below

these items, unless a 4

foot horizontal distance

is maintained.

The vertical termination MUST be a minimum

of 3 feet (0.9 m) above the point of exit in the

rooftop.

A vertical termination less than 10 feet

(3.05 m) from a parapet wall MUST be a

minimum of 2 feet (0.6 m) higher than the

parapet wall.

The vent cap shall terminate at least 3 feet

(0.9 m) above any forced air inlet within 10

feet (3.05 m). The vent shall terminate at least

4 feet (1.2 m) below, 4 feet (1.2 m)

horizontally from or 1 foot (0.30 m) above

any door, window, or gravity air inlet to the

building.

Do not terminate the vent in a window well, stairwell,

alcove, courtyard, or other recessed area. The vent

cannot terminate below grade.

MASONRY CHIMNEY

A masonry chimney MUST be properly sized

for the installation of a high efficiency gas fired

appliance. Venting of a high efficiency

appliance into a cold or oversized masonry

chimney can result in operational and safety

problems.

Exterior masonry chimneys, with one or more

sides exposed to cold outdoor

temperatures, are more likely to have

venting problems. For this reason, exterior

masonry chimneys are not generally

recommended to vent high efficiency gas

appliances.

An interior masonry chimney, which is not

exposed to the outdoors below the roofline,

may be used to vent high efficiency gas

appliances based on the results of careful

inspection, proper sizing and local code

approval. If there is any doubt about the sizing

or condition of a masonry chimney, it MUST

be relined with a properly sized and approved

chimney liner system.

An interior masonry chimney MUST be

carefully inspected to determine its suitability

for the venting of flue products.

A clay tile lined chimney MUST be structurally

sound, straight and free of misaligned tile,

gaps between liner sections, missing sections

of liner or any signs of condensate drainage at

the breeching or clean out. If there is any

doubt about the condition of a masonry

chimney, it MUST be relined.

Metallic liner systems (Type “B” double-wall,

flexible, or rigid metallic liners) are

recommended to line or reline an existing

masonry chimney. Consult with local code

officials to determine code requirements or

the advisability of using a lined masonry

chimney or relining of a masonry chimney.

Lochinvar DESIGNER’S GUIDE EFFICIENCY+ WATER HEATER 615-889-8900 7

NOTE:

An unlined masonry

chimney MUST NOT be

used to vent flue

products from this high

efficiency appliance.

8 Lochinvar DESIGNER’S GUIDE EFFICIENCY+ WATER HEATER 615-889-8900

CONVENTIONAL VENTING –

NEGATIVE DRAFT

Size vent material according to the “FAN”

column of vent sizing tables in the latest edition

of the National Fuel Gas Code.

“FAN” applies to Category I fan-assisted

combustion appliances with natural draft.

Utilize Category I Type “B” vent material

for all conventional venting applications.

A bell increaser is provided and installed

directly on the water heater vent outlet.

The bell increases the water heater vent

size by 1 inch (25.4 mm) in diameter. The vent

connection is made directly to the bell

increaser on the top of the unit. No additional

draft diverter or barometric damper is

required.

When each unit is installed with an individual

vent, and the negative draft is higher than the

specified range of 0.02 to 0.05 inches of

water column, a barometric damper will be

necessary.

Multiple unit installations with combined

venting require barometric dampers to regulate

draft at each unit. The negative draft MUST

be within the range of 0.02 to 0.05 inches of

water column to ensure proper operation.

All draft readings are made while unit is in

stable operation (approximately 2 to 5

minutes).

Lochinvar

(FIG. 7) MULTIPLE UNIT BAROMETRIC

DAMPER INSTALLATION

WATER HEATER/BOILER

BAROMETRIC DAMPER ON SINGLE UNIT INSTALLATION

Lined

Chimney

WATER HEATER/BOILER

BAROMETRIC DAMPER ON SINGLE UNIT INSTALLATION

(FIG. 6) BAROMETRIC DAMPER INSTALLATION

(TABLE B)

CONVENTIONAL VENTING, VENT CONNECTION SIZE

MODEL DIAMETER

EW 150 5”

EW 200 5”

EW 250 6”

EW 300 6”

NOTE:

An unlined masonry

chimney MUST NOT be

used to vent flue

products from this high

efficiency appliance.

For this type of installation, it is best to use a

draft control for each water heater located on

the riser between the vent outlet and the

breeching – Location “A”.

When this riser is too short to permit the

installation of a control, locate a separate

control for each water heater on the main

breeching as illustrated in Location “B”.

If, because of general crowding or other

reasons, neither of these locations are

possible, use a single large control in the

breeching between the water heater nearest

the chimney and the chimney, as shown in

Location “C”.

CONVENTIONAL VENTING WITH DIRECT

COMBUSTION AIR INTAKE (E+ DIRECTAIRE VENT)

This vent system uses two pipes, one vertical

pipe with a roof top termination for the flue

products and one pipe for combustion air. The

combustion air pipe may terminate horizontally

with a sidewall air inlet or vertically with a roof

top air inlet. All instructions for “Conventional

Venting Negative Draft” apply to

“Conventional Venting with Direct Combustion

Air”. The flue may be combined with the vent

from any other negative draft, Category I

appliances. Utilize Category I Type “B” vent

material for venting flue products.

The sidewall or vertical roof top E+ DirectAire

Vent combustion air supply system has specific

vent material and installation requirements.

The air inlet pipe connects directly to the water

heater to supply combustion air. In most

installations, the combustion air inlet pipe will

be a dedicated system with one air inlet pipe

per water heater. Multiple air inlets may be

combined if the guidelines in “Combined Air

Inlet Points” are followed. The air inlet pipe will

be connected to a combustion air inlet cap as

specified in this section. Combustion air

supplied from outdoors MUST be free of

contaminants. The air inlet pipe(s) MUST be

sealed. Select air inlet pipe material from the

following specified materials:

• PVC, CPVC or ABS (3”, 4”, 5” or 6” I.D.).

• Dryer vent (not recommended for roof top

air inlet).

• Galvanized steel vent pipe with joints and

seams sealed.

• Type “B” double wall vent with joints and

seams sealed.

The total equivalent length of the sidewall or

vertical roof top E+ DirectAire Vent combustion

air inlet pipe MUST NOT exceed a maximum

of 50 (15.2 m) equivalent feet in length.

Subtract 5 feet (1.5 m) for each elbow in the

air intake system.

Lochinvar DESIGNER’S GUIDE EFFICIENCY+ WATER HEATER 615-889-8900 9

10 Lochinvar DESIGNER’S GUIDE EFFICIENCY+ WATER HEATER 615-889-8900

SIDEWALL AIR INLET

The sidewall air inlet cap is supplied in the

E+ DirectAire Sidewall Vent Kit. Each kit

includes a sidewall combustion air inlet cap to

supply air to a single water heater and

instructions for proper installation. The part

number for each kit is listed by unit size.

Locate units as close as possible to sidewall

where the combustion air supply system will be

installed.

To prevent recirculation of flue products from

an adjacent vent cap into the combustion air

inlet, follow all applicable clearance

requirements in the latest edition of the

National Fuel Gas Code and instructions in

this guide.

The combustion air inlet cap MUST be placed

at least one foot (0.3 m) above ground level

and above normal snow levels.

ROOFTOP AIR INLET

The air inlet cap for the vertical roof top air

inlet is assembled from components purchased

locally. The air inlet cap consists of two 90°

elbows installed at the point of termination for

the air inlet pipe.

The point of termination for the combustion air

inlet cap MUST be at least 2 feet (0.6 m)

below the point of flue gas termination (vent

cap), if it’s located within 10 feet (3.05 m) of

the flue outlet.

The termination ell on the air inlet MUST be

located a minimum of 12” (0.30 m) above the

roof or above normal levels of snow

accumulation. It MUST NOT be placed closer

than 10 feet (3.05 m) from an inside corner of

an L-shaped structure.

Incorrect location of the air inlet cap can allow

the discharge of flue products to be drawn into

the combustion process of the water heater.

Lochinvar

(FIG. 9) E+ DIRECTAIRE VENT WITH VERTICAL AIR INLET

(FIG. 8) E+ DIRETAIRE VENT WITH SIDEWALL AIR INLET

(TABLE C)

E+ DIRECTAIRE VENT SIDEWALL AIR KIT PART NUMBERS

CONVENTIONAL VENT AIR VENT KIT

MODEL NUMBER FLUE SIZE* INLET SIZE PART NUMBER

EW 150 5” 4” SVK 3020

EW 200 5” 4” SVK 3020

EW 250 6” 5” SVK 3021

EW 300 6” 5” SVK 3021

NOTE:

The use of double wall

vent material

for the combustion air

inlet pipe is

recommended in cold

climates to prevent the

condensation of airborne

moisture

in the incoming

combustion air.

*Vent size with 1” increaser installed for conventional negative

draft venting.

This can result in incomplete combustion and

potentially hazardous levels of carbon

monoxide in the flue products.

COMBINED AIR INLET POINTS

The air inlet pipes from multiple water heaters

can be combined into a single common

connection, if the common air inlet pipe has a

cross sectional area equal to or larger than the

total area of all air inlet pipes connected to the

common air inlet pipe.

The air inlet point for multiple water heater air

inlets MUST be provided with an exterior

opening which has a free area equal to or

greater than the total area of all air inlet pipes

connected to the common air inlet. This

exterior opening for combustion air

MUST connect directly to the outdoors.

The total length of the combined air inlet pipe

MUST NOT exceed a maximum of 50 feet

equivalent feet (15.2 m). Deduct the restriction

in area provided by any screens, grills or

louvers installed in the common air inlet point.

Screens, grills, or louvers installed in the

common air inlet can reduce the free area of

the opening from 25% to 75% based on the

materials used.

The air inlet cap for the combined air supply from

multiple water heaters MUST be purchased or

fabricated in the field.

DIRECT VENTING

POSITIVE PRESSURE

A direct vent water heater uses a two pipe

system, one pipe for the flue products and one

pipe for the combustion air supply. The flue

CANNOT be combined with any other appliance

vent or common vent from multiple water heaters.

The vent on a direct vent system will have a

positive pressure in the flue, which requires all

vent joints and seams to be sealed gas-tight. The

flue from a direct vent system MUST have a

condensate drain with provisions to properly

collect and dispose of any condensate that may

occur in the venting system. Direct vent systems

require Category IV vent material with AL29-4C

approved stainless steel.

The air inlet pipe connects directly to the water

heater to supply combustion air. The air inlet pipe

MUST be sealed. Choose acceptable

combustion air pipe materials from those

specified in this section.

Approved material for air inlet pipes include:

PVC, CPVC or ABS (4”, 5” or 6” I.D.), dryer

vent, and galvanized steel vent pipe with joints

and seams sealed.

The total equivalent length of the direct vent flue

pipe or the air inlet pipe MUST NOT exceed a

maximum of 50 equivalent feet (15.2 m) in length

for each pipe. Subtract 5 feet (1.5 m) for each

elbow in the vent pipe or air intake system.

EXAMPLE OF

COMBINED AIR

INLET SIZING

Two 5” air inlet pipes

(19.6 in

area each) have

a total area of 39.2 in

requiring an 8” (50.3 in

area) common air inlet

pipe.

Lochinvar DESIGNER’S GUIDE EFFICIENCY+ WATER HEATER 615-889-8900 11

HORIZONTAL DIRECT VENT

Horizontal direct vent applications require

a vent kit which MUST be supplied by

Lochinvar to guarantee proper operation.

The part number for each kit is listed by unit

size. Each kit includes a sidewall vent cap for

flue products, a firestop, a combustion air inlet

cap and instructions for proper installation.

It is important to be careful in the placement of

the horizontal direct vent caps. Combustion air

supplied from outdoors MUST be free of

contaminants.

To prevent recirculation of flue products into the

combustion air inlet:

The combustion air inlet cap MUST NOT

be installed above the flue outlet cap.

Maintain a minimum 3 foot (0.9 m) radius

clearance between the combustion air inlet

cap and the flue outlet cap.

The combustion air inlet cap and vent cap

for flue outlet MUST be located on the same

sidewall and in the same pressure zone.

DO NOT place the combustion air inlet

cap closer than 10 feet (3.0 m) from an

inside corner of an L-shaped structure.

Place the combustion air inlet cap at least

1 foot (0.3 m) above ground level and

above normal snow levels.

MULTIPLE UNIT APPLICATIONS

Horizontal Direct Vent

The combustion air inlet caps for multiple unit

installations MUST maintain the minimum 3

foot (0.9 m) radius clearance below or

horizontally from the closest flue outlet.

Lochinvar

12 Lochinvar DESIGNER’S GUIDE EFFICIENCY+ WATER HEATER 615-889-8900

CAUTION!

Water heaters which

are shut down or will

not operate may

experience freezing due

to convective air flow in

the air inlet pipe

connected to the unit.

Proper freeze

protection MUST be

provided.

(TABLE D)

–

HORIZONTAL DIRECT VENT KITS

MODEL DIRECT VENT AIR INLET HORIZONTAL DIRECT

NUMBER FLUE SIZE* PIPE* VENT KIT

EW 150 4” 4” HDK3013

EW 200 4” 4” HDK3013

EW 250 5” 5” HDK3013

EW 300 5” 5” HDK3014

(FIG. 10) HORIZONTAL DIRECT VENT

(FIG. 11) HORIZONTAL DIRECT VENT CAPS

NOTE:

The use of double wall

vent material for the

combustion air inlet pipe

is recommended in cold

climates to prevent the

accumulation of

condensation on the pipe

exterior.

*Minimum diameter, installer may increase diameter one pipe

size for ease of installation if needed.

Multiple flue outlet caps may be installed side

by side, and multiple air inlet caps may be

installed side by side, but the 3 foot (0.9 m)

radius minimum clearance between air inlet

and flue outlet MUST be maintained.

All clearance and installation requirements in

this section and the applicable portions of the

general venting section MUST be maintained

on multiple unit installations.

VERTICAL DIRECT VENT

Vertical direct vent applications do not

require a vent kit to be supplied by Lochinvar.

The vent cap and air inlet cap for vertical

direct vent applications are fabricated or

purchased in the field. A vertical vent cap, as

specified by the vent material manufacturer, is

used to vent the flue products to the outdoors.

The air inlet cap consists of two 90° elbows

installed at the point of termination for the air

inlet pipe. The termination ell on the air inlet

MUST be located a minimum of 12” (15.2 cm)

above the roof or above normal levels of snow

accumulation. The point of termination for the

air inlet MUST be 24” (0.6m) lower than the

point of flue gas termination, if it is located

within 10 feet (3.05 m) of the flue outlet.

Incorrect installation and/or location of the air

inlet cap can allow the discharge of flue

products to be drawn into the combustion

process on the water heater. This can result in

incomplete combustion and potentially

hazardous levels of carbon monoxide in the

flue products.

MULTIPLE UNIT APPLICATIONS

Vertical Direct Vent

The combustion air inlet caps for multiple unit

installations MUST maintain the minimum 2 foot

(0.6 m) clearance below the closest vertical flue

outlet if within 10 feet (3.05 m).

Multiple flue outlet caps may be installed side

by side and multiple air inlet caps may be

installed side by side, but the air inlet MUST

always be at least 2 feet (0.6 m) below the

closest flue outlet if the outlet is within 10 feet

(3.05 m).

Lochinvar DESIGNER’S GUIDE EFFICIENCY+ WATER HEATER 615-889-8900 13

(FIG. 13) VERTICAL DIRECT VENT

(TABLE E) – VERTICAL DIRECT VENT,

FLUE AND AIR INLET SIZES

MODEL DIRECT VENT AIR INLET

NUMBER FLUE SIZE PIPE

EW 150 4” 4”

EW 200 4” 4”

EW 250 5” 5”

EW 300 5” 5”

(FIG. 12) MULTIPLE SIDEWALL DIRECT VENT CAPS

AIR INLETS

3’ MIN.

FLUE OUTLETS

14 Lochinvar DESIGNER’S GUIDE EFFICIENCY+ WATER HEATER 615-889-8900

OUTDOOR INSTALLATION

Units are self venting and can be used outdoors

when installed with the optional Outdoor Vent

Kit. This kit includes a one piece top cover

which replaces the standard two piece cover,

air inlet cap, exhaust cap and gas valve cover.

The cap mounts directly to the top of the water

heater and covers the flue outlet and combustion

air inlet openings on the jacket. No additional

vent piping is required. Maintain a minimum

clearance of 3" (76mm) to combustible surfaces

and a minimum of 3" (76 mm) clearance to the

air inlet. An outdoor unit should not be located

so that high winds can deflect off of adjacent

walls, buildings or shrubbery causing

recirculation. Recirculation of flue products may

cause operational problems, bad combustion or

damage to controls. The unit should be located

at least 3 feet (0.91m) from any wall or vertical

surface to prevent adverse wind conditions from

affecting performance.

Multiple unit outdoor installations require 48"

(1.22m) clearance between each vent cap. The

outdoor cap must be located 4 feet (1.22m)

below and 4 feet (1.22m) horizontally from any

window, door, walkway or gravity air intake.

The combustion air inlet of the outdoor cap must

be located at least one foot (0.30m) above

grade and above normal snow levels. The

water heater must be at least 10 feet (3.05m)

away from any forced air inlet and at least 3

feet (0.91m) outside any overhang. Do not

install in locations where rain from building

runoff drains will spill onto the water heater.

Lochinvar must furnish an outdoor vent kit in

accordance with CSA international

requirements. Each kit includes the flue

outlet/combustion air inlet, gas valve cover,

piece unit top and pump cover.

Freeze Protection-

Outdoor Installation

A snow screen should be installed to prevent

snow and ice accumulation around the

appliance or its venting system.

If for any reason the unit is to be shut off:

(a.) Shut off water supply.

(b.) Drain unit completely.

(c.) Drain pump and piping.

If freeze protection is not provided for the

system, a low ambient temperature alarm or

automatic drain system is recommended.

Lochinvar

(FIG. 14) OUTDOOR VENTING

(TABLE F)

–

OUTDOOR VENT KITS

MODEL OUTDOOR

NUMBER VENT KIT

EW150 ODK3062

EW200 ODK3063

EW250 ODK3067

EW300 ODK3068

*Minimum diameter, installer may increase diameter one pipe

size for ease of installation if needed.

GAS SUPPLY

Safe operation of unit requires properly

sized gas supply piping (See TABLE F).

Gas pipe size may be larger than the

heater connection.

An internal gas pressure regulator is required

if upstream pressure exceeds 6 oz. (10.5"

water column), an intermediate gas

pressure regulator, of the lockup type,

MUST be installed.

Installation of a union is suggested for ease

of service.

Install a manual main gas shutoff valve with

test plug, outside the appliance gas

connection and before the gas valve, when

local codes require.

A trap (drip leg) should be provided in the

inlet of the gas connection to the unit.

HIGH ALTITUDE APPLICATIONS

Atmospheric pressure decreases as the height

above sea level increases. At any altitude above

sea level, a cubic foot will contain less gas than a

cubic foot at sea level. Thus, the heating value of a

cubic foot of fuel gas will decrease as height above

sea level increases. Specific gravity of a gas with

respect to sea level also decreases with altitude.

These changes in heating value and specific

gravity tend to offset each other. However, as

elevation above sea level is increased, there is

less oxygen per cubic foot of air. Therefore,

heat input rate should be reduced in an

appliance above 2000 feet. Ratings should

be reduced at the rate of 4 percent for each

1000 feet above sea level.

WATER CONNECTIONS

Lochinvar DESIGNER’S GUIDE EFFICIENCY+ WATER HEATER 615-889-8900 15

(TABLE H) – INLET GAS PRESSURE REQUIREMENTS

NAT. GAS LPG

MAX. (INCHES-WATER COLUMN) 10.5” w.c. 13” w.c.

MIN. (INCHES-WATER COLUMN) 4.7” w.c. 8” w.c.

EXAMPLE OF

HIGH ALTITUDE

APPLICATIONS

For example, if a unit’s

input is 200,000 Btu/hr

at sea level, the rated

input at 4000 feet of

elevation can be

calculated by derating

input 4% per 1000 feet

above sea level.

[Btu/hr Input]

[1.00 - (Elevation/

1000 ft. x 0.04)] =

Btu/hr Input at

specified elevation.

[200,000][1.00 -

(4000 ft./1000 ft. x

0.04)] = Btu/hr Input

4000 ft. elevation.

[200,000][0.84] =

168,000 Btu/hr Input

at 4000 ft. elevation.

(TABLE G) – GAS SUPPLY PIPE SIZING

Length of Pipe In Straight Feet

Nominal Iron

Pipe Size, Inches 10 20 30 40 50 60 70 80 90 100 125 150 175 200

369 256 205 174 155 141 128 121 113 106 95 86 79 74

697 477 384 328 292 267 256 246 210 200 179 164 149 138

1,400 974 789 677 595 543 502 472 441 410 369 333 308 287

2,150 1,500 1,210 1,020 923 830 769 707 666 636 564 513 472 441

4,100 2,820 2,260 1,950 1,720 1,560 1,440 1,330 1,250 1,180 1,100 974 871 820

6,460 4,460 3,610 3,100 2,720 2,460 2,310 2,100 2,000 1,900 1,700 1,540 1,400 1,300

11,200 7,900 6,400 5,400 4,870 4,410 4,000 3,800 3,540 3,300 3,000 2,720 2,500 2,340

23,500 16,100 13,100 11,100 10,000 9,000 8,300 7,690 7,380 6,870 6,150 5,640 5,130 4,720

Maximum capacity of pipe in thousands of BTU’s per hour for gas pressures of 14” Inches Water Column (0.5 PSIG) or less and a total

system pressure drop of 0.05 Inch Water Column (Based on NAT GAS, 1025 BTU’s per Cubic Foot of Gas and 0.60 Specific Gravity).

16 Lochinvar DESIGNER’S GUIDE EFFICIENCY+ WATER HEATER 615-889-8900

Lochinvar

INLET AND OUTLET WATER CONNECTIONS

For ease of service, install unions on inlet and

outlet of the water heater. The connection on the

unit marked “Inlet” should be used for return

water from the storage tank. The connection on

the header marked “Outlet” should be

connected to the inlet of the storage tank. (See

Appendix A Water Heater Piping diagrams).

WATER VELOCITY CONTROL

IMPORTANT

To ensure proper velocity through the heat

exchanger, it is necessary to regulate the

temperature rise across the heat exchanger from

inlet to outlet. (This MUST be done on initial

installation and periodically rechecked.)

With the correct temperature rise across the heat

exchanger (See TABLE I), you may be assured of

the proper velocity in the tubes and long life and

economical operation from the water heater.

LOW WATER TEMPERATURE

DELIVERY

A number of water heating applications may

require delivered water temperature in a system

below 140°F. Systems such as nursing homes

and hospitals would be examples of this type of

system. A water heating system that will be

operated at less than 140°F MUST use a

mixing valve

on the outlet side of the storage

tank in order to ensure that the products of

combustion do not condense inside the

combustion

chamber of the water heater. The

mixing valve allows the water heater to operate

above 140°F to protect from condensation, while

still allowing a delivery of colder water to the

system fixtures. Also inherent in this design is the

protection of occupants from water containing

bacteria such as Legionella. Legionella can be

significantly reduced in the water storage vessel

by heating the water to a minimum of 140°F.

(See Appendix A for piping details.)

PUMP OPERATION

The water heater MUST be connected

with a properly sized and installed,

intermittent operating, all bronze pump that

circulates water between heater

and storage tank.

Pump is sized to heater input and water

hardness. Should water hardness exceed 25

grains/350 TDS per gallon, consult factory

for pump sizing.

The pump chart (Table J) is based on the

following fittings:

6-90° elbows

2 unions

2 ball valves

1 cold water supply tee

Due to pump capacity the following specifications cannot

be exceeded when using the standard pump:

•Not more than 45 feet of straight pipe

NOTE:

A larger pump

MUST be utilized in

situations where the

distance between the

water heater and tank

exceed those specified.

(TABLE I) – REQUIRED TEMPERATURE RISE

MODEL NUMBER TEMPERATURE RISE °F

EW 150 4.6

EW 200 6.2

EW 250 7.7

EW 300 9.3

NOTE:

Care should be

taken to measure

temperature rise

and maintain proper

water velocity in the

heat exchanger.

NOTE:

When the unit is installed

in Canada, it MUST

conform to the CSA

C22.1, Canadian Electrical

Code, Part 1, and/or local

Electrical Codes.

NOTE:

Incorrect piping of the

cold water supply to the

system will result in

condensate formation on

the heat exchanger and

operational problems.

See installation

drawings provided with

the unit for correct

piping. Higher water

temperatures reduce

condensate formation.

Refer to drawings

in Appendix.

•For every elbow and tee in excess of

those shown above, DEDUCT 5 FEET

from maximum allowable straight pipe

in heater-to-tank circulating loop.

WATER TREATMENT

In hard water areas, water treatment should be

used to reduce introduction of minerals into the

system. Minerals in the water can collect in the

heat exchanger tubes causing noise and

inefficient operation. Excessive build-up of

materials in the heat exchanger can cause a

non-warrantable failure.

Acceptable Water Quality Levels

Maximum Water Hardness = 25 Grains

Minimum Water Hardness = 5 Grains

Maximum Total Dissolved Solids = 350 PPM Range of

Acceptable pH = 7.2 to 7.8

Standard production Lochinvar water heaters are

designed to operate free of impurity build-up in the

heat exchanger when properly installed and

operated under the specified water quality

conditions. For installation in areas outside these

parameters, please consult the factory.

WATER FLOW SWITCH

Due to the low water content (between 1 and 6

gallons) of the copper finned tube heat exchanger,

a flow switch is factory installed as a low water

cutoff device on models EW 150 through EW 300.

The flow switch is installed in the outlet piping from

the water heater and wired in series with the

ignition system safety controls. A flow switch is

acceptable as a low water cutoff device on water

heaters requiring forced circulation. It is prudent to

verify acceptance with the local code official.

RELIEF VALVE

This water heater is supplied with temperature

and pressure relief valve(s) sized in

accordance with ASME Boiler and Pressure

Vessel Code, Section IV “Heating Boilers.”

ELECTRICAL REQUIREMENTS

(North America)

The appliance is wired for 120 volts.

All wiring between the unit and field

installed devices shall be made of type

T wire [63

°F (35°C) rise].

The pump MUST be wired to run

continuously when unit is firing.

It is recommended that the water heater

and pump be wired on separate circuits

with properly sized breakers.

(TABLE K)

COMMON WATER MANIFOLD PIPE SIZE FOR MULTIPLE WATER HEATER

INSTALLATIONS

NUMBER COMMON MANIFOLD PIPE SIZE (MINIMUM)

OF UNITS EW 100 EW 150-300

” 2”

22” 3”

” 3

”

43” 4”

” 5”

(TABLE L) – AMP DRAW DATA

MODEL FAN CONTROLS PUMP APPROXIMATE

NUMBER TOTAL AMPS

@ 120 VAC

EW 150-300 1.2 4.0 5.8 11.0

Lochinvar DESIGNER’S GUIDE EFFICIENCY+ WATER HEATER 615-889-8900 17

(TABLE J)

REQUIRED PUMP PERFORMANCE FOR WATER HARDNESS OF 5

TO 25 GRAINS

MODEL GPM FT. HD. AMP HORSE VOLTAGE/

DRAW POWER PHASE

EW 150-300 55 10 5.8 1/4 120/1

EFFICIENCY+

WATER HEATER

PIPING DIAGRAMS

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Lochinvar EW 250 Designer's Manual

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Model: EW 250

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